Apparatus for shaping metal plates



Jan. 8, 1952 5, P BENES 2,581,622

APPARATUS FOR SHAPING METAL PLATES Filed Feb. 15. 1946 2 Si-XEETS-SHEET l I Lgnvenzor" 645 0 07'' P562265 Jan. 8, 1952 G. P. BEN'ES 2,581,622

APPARATUS FOR SHAPING METAL PLATES Filed Feb. 15, 1946 2 Sl-IEETS-5l-IEET 2 59. 4. I? l f L L J5 Patented Jan. 8, 1952 APPARATUS FOR SHAPING METAL PLATES Gaspar P. Benes, Cleveland, Ohio, assignor to Addressograph-Multigraph Corporation, Wilmington, Del., a corporation of Delaware Application February 15, 1946, Serial No. 647,899

1 Claim. I

This invention relates to a method and apparatus for shaping metal plates, and is particularly applicable to the manufacture of small printing plates such as are used in addressing machines and the like. Plates of the character referred to are described in detail in Letters Patent, Serial No. 591,738, filed May 3, 1945, and now Patent No. 2,425,325, granted August 12, 1947, to Carl J. Hueber and William J. Hampton, and assigned to the assignee of the present application.

As described more fully in said Hueber and Hampton application and as well known in the are now, printing devices of a type commonly used in addressing machines and the like embody a frame or carrier on which at least one embossable printing plate is releasably retained. It has been found that the most satisfactory way in which type characters may be embossed on such embossable plates is to press the material of such a plate upwardly, in the course of a type embossing operation, so as to form a protuberance including a flat top to afford a raised panel. The desired type character is raised above the general level of the plate by its own height and by the height of the panel.

However, the means which retain the plate on the frame just mentioned are frequently so nearly as high as the type surface, that resort is usually had to guards or the like which cover the retaining means to avoid an impressionbeing made from such means when an impression is made from the. type characters. The Hueber et a1. application points outthat this may be avoided, to a, large degree, by shaping the edges of the plate so that plate retaining elements of less thickness or height above the plate may be utilized, giving greater clearance between. the plate retaining means and the sheet to be printed, and obviating the difficulties mentioned.

. My' invention provides a method and means for accomplishing the shaping of the edges of plates to thus accommodate plate retaining means which will provide greater clearance in printing. More specifically, an object of my invention is to provide a simple and effective meth- 0d and apparatus for providing a rabbet or bevel on the edge of a thin metal plate, such as an embossable address plate of the type used in addressing and related business machines. A further object of my invention is to reduce the thickness of edge portions of plates of the type referred to above, by rolling or swaging in such a manner that the fiow of metal does not produeerough, sharp edges or corners, and insuch a manner that part of the metal which flows in a rolling or swaging operation serves to thicken and reinforce the body of the plate along an area adjoining the portions which are reduced in thickness. It is still another object of my invention to roll or swage thin plates, as aforesaid, in such a manner that strains in such plates, which might otherwise cause bending or distortion as a result of the flow of metal, are effectively neutralized.

Other and further objects of the present invention will be apparent from the following description and claims and are illustrated in the accompanying drawings which, by Way of illustration, show preferred embodiments of the present invention and the principles thereof and what I now consider to be the best mode in which I have contemplated applying these principles. Other embodiments of the invention embodying the same or equivalent principles may be used and structural changes may be made as desired by those skilled in the art Without departing from the present invention and the purview of the appended claim.

In the drawings:

Fig. 1 is a side elevational View of an apparatus embodying my invention;

Fig. 2 is an end elevational view of the apparatus shown in Fig. 1; 1

Fig. 3 is a fragmentary vertical sectional view through the rolls and the bearings of the apstantially on the line 3--3 on Fig. 2;

Fig. 3A is a fragmentary sectional view show ing part of the elements seen in Fig. 3;

Fig. 4 is a, sectional view drawn to a greatly enlarged scale of a swaged plate produced by the method and apparatus of my present invention; and

Fig. 5 is a sectional view, also drawn to a greatly enlarged scale, of a swaged plate of modified form, produced by the method and apparatus of my present invention.

Printing plates of the general character to which my invention is applicable are shown in Gollwitzer Patent Re. No. 22,249, Mohler Patent No. 1,812,894, Berthelsen Patent No. 1,929,472, and more particularly in the aforesaid copending application of Hueber et al., Serial No. 591,738. Plates of the character described as above, and particularly in the Hueber et al. application, are of thin metal sheet, having a, thickness, for ex ample, of .012 to .018", prior to treatment by.

my method and apparatus. Such a sheet, having rectangular edges, is rolledor swaged by my method and apparatus to reduce the thickness of the edge portions in a stepwise or rabbet formation, as shown in Fig. 4, at P or in a beveled formation, as shown in Fig. at Pb. By way of example, the edge portions 12 in Fig. 4 may be reduced to a thickness of about or a little more than half the original thickness of the plate. The forming operation causes metal to flow outwardly, widening the plate slightly and causing its edges to become somewhat round and smooth as shown at I8, I9. The operation also causes metal to flow inwardly, thereby causing the plate thickness to increase slightly along the margin of the swaged area, as indicated at H. The actual increase in thickness may be of the order of one or two thousandths of an inch, such increase being unobjectionable and even advan'- tageous as it reinforces the plate slightly. The added thickness also provides higher shoulders I5 and 16, Fig. 4, against which plateretaining means may abut to hold the plate firmly .on a printing device. In the alternate form shown in Fig. :5, the plate Pb is rolled, or swaged to provide beveled edges l2b. Retaining devices, not shown herein but described in detail .in the aforesaid Hueber et a1. applicationmay hold the plates :P or Pb to a frame member by engaging the thin margins, .thus reducing their overall height from that required when they engage the full thickness of the plate. This reduction in overall height makes the .diiference, in most cases, between a clean and a 'smudged impression from the printing device. The particular manner and means by which these .edges ofredue-ed thickness are produced will now beset forth, in detail.

Referring now to Figs. 1, 2, 3 and 4, an apparatus exemplary of my invention is shown as a rolling mill including a stand 2! embodying Spaced uprights which support the .roller elements. The general arrangement .is that .of a standard two-high rolling mill. Bearings. 22 and 23 are, provided. near the lower ends of the uprights and the shaft 24 of the lower roll 25 is journaled therein. Other bearings 26 and 12'! are provided in the uprights of the stand 2| respectively above the bearings 22 and 23. Preferably these latter bearmgs are contained in cages that are mounted for vertical movement in the uprights in such away thatmanipulation of .a hand wheel 28 "or the like will cause. bearings 26 and 2'! to move, respectively, relativeto the bearings 22 and 23. The interconnection between the hand wheel '28'and the cages for the bearings 26 and 2'! is preferably of such character that a material movement of the handwheel 28 .is required to effect a relatively slight movement of the cages and the bearings 26, 21. In other words there is a large gear reduction, or the. equivalent so that relatively fine adjustment in the position of the cages and their bearings may be realized. A worm. worm wheel, and threaded shaft arrangement is suitable. As indicated at 28c, anappropriate scale may be provided on handwheel 28v to facilitate its adjustment. 7

An upperroll shaft 29 1s journaled in the bearings 26 and 21 and the upper roll, generally indicated at 30, is mounted on this shaft. .As best shown in Fig. 3, this roll .30 isof sectional con, struction and the sections thereof are'heldttogether by locking nuts as 31 and 32 mounted on screw threaded portions of the shaft 29. .The

sectional, portions of. roll 30,1whichcooperate with a-large, smooth, .solidisurface .of .roller 25, come p fifi two r n membersv 83 .arrd M which '.are,1in

effect, rolling collars of equal diameter spaced apart a distance equal to that between theshou1- ders l5, I6 01 the plate P, Fig. 4, or equal to that between the inner upper edges of the bevels llb, Fig. '5. Collars 33, 34 are of hard steel or the like, are shaped to produce the type of edge desired on the plate P or Pb, and are capable of rolling or swaging a smooth surfaced plate edge to the thickness and configuration required. Suitable drive means, not shown, may be provided for shafts 24 and 29 and associated parts of the machine.

Between the rollingcollars 33 and 34 a spacing collar 35 is provided and all three collars are keyed "to shaft 29 in an appropriate manner to cause positive rotation therewith. A collar 36 of firmly resilient naterial, such as natural or synthetic rubber of appropriate grade and type, is mounted on collar 35 for rotation therewith. The outer diameter of. the resilient collar or band 35. :is preferably .of theyesame diameter as the collars 33,34, aseshowniniig. 3A.

As suggested above, the collar 35 and the resilient collar .36 are of theproper width to space the rolling collars apart a distance equal tothe width of the .unrolled portions .of the plate P or Pb. Printing plates of the type used in addressing machines and :related business machines are of various widths, andJitis :obvious that collars 35 and .36 may be provided inseveral widthsas de sired, to provide for rolling shaped edges on plates of various widths. The smooth surface .of the backing roller 25 and the smooth middle portion of .roller 3|], between the threaded portions for locking'rings 3| :and 32 are of sufiicient width to roll the widestplates used.

When blanks, =as.'E ,.Fig.i3,1are .to have flanges as I2 swaged .orrolled thereon, to provide plates as P, Fig. 4 the band wheel 28 is manipulated to space the peripheries of :rolling .collars '33 and 34 from the smooth cylindrical surface of the.

lower roller 25 in an amount corresponding to portions of flanges as 12. As .best shown in Fig. 2, a supply table :as :31 leads .to'a point adjacent the bite between the rolling collars 33, 3:4 and the lower :rol1er25. Blanks E :are fed over this table by any conventional feeding means, not

shown, between or through-suitable accuratelylocated guides'to insure accurate movement of the blanks, E into the .bite between the rollingmembers. After passage "of the blanks E through the aforesaid .bite, these blanks, now in the form .01

plates .P, pass on to a discharge table as'38 to be collectedand stacked or packaged in a suitable manner.

The guides which are efiective to direct the blanksv asEufrom-theieed .table 31 to the rolling members25, 33, 3:4, are so located thatthe .center line between the longitudinal (in the direction of movement) edges. of ahlank misaligned with the centerlines between the inner .edgesof the rolling collarse33 and34. This insuresthat the portions .of .theblanks E, where theshouldersas i5 and l 6 :are .to'be formed respectively move into engagement with theinner edges :of'the rolling collars33 andBA. Hence when marginal, portions along blanks as E pass betweenthe rolling collars 33 and 34 and the periphery of the lower roll 25, flanges as I2 whicharesw-aged along the mar gineltl; portions :of the blank define theshonlders l5, 1

.As explained above, the diameter of the resilientcollar-is preferably equal to the diameter-ofrolling collars 33 and '34 {to facilitate grindingthe assembled roller to an accurate uniform size. With this construction, as shown in Figs. 3 and 3A, when marginal portions of the blanks E are passing between the collars and the lower roll, as described above, the resilient collar 36 is flattened or reduced in thickness so as to have prolonged contact with the face of the blank E in..the portion thereof lying between shoulders l5, l6, Fig. 4. The reduction in thickness of the collar 33 is equal to the height of shoulders [5, I6, Fig. 4. In the production of a beveled edge, Fig. 5, the resilient collar 36 would be of a diameter and so arranged with respect to the rolling collars that a similar degree of compression would result. In this case obviously the rolling collars would be shaped suitably to form the desired bevel.

This prolonged contact between the resilient collar 36 and the body of.the plate P, resulting from compressionof the resilient collar, counteracts the tendency of the plate to bend or bow in response to stresses impressed by the swaging of the marginal portions thereof. The degree of resiliency of the collar 36 is determined empirically. If this collar is too hard it exerts a rolling and reverse binding effect on the blank which overcompensates for the bowing effect of the swaging operation under collars 33 and 34. On the other hand, if the resilient collar 38 is not hard enough to fully counteract the effect of stresses imposed on the plate by collars 33, 34 then the plate or blank, as E, will bow under the influence of the stresses set up by swaging. It will be noted that the compression of the resilient collar 36 causes the effect of a flow of rubber through a restricted channel defined by lower roll 25, collars 33, 34', and collar 35. Because of its restricted cross section, this channel causes the outer periphery of the rubber collar 36 to in effect flow past its central point of contact with the blank, thus to move more rapidly at this point than the blank E, the rate of movement of the latter being controlled by the swaging members 25, 33, and 34, which have a firm grip thereon. In effect, therefore, the surface of the resilient or rubber collar 36 applies a force tangential to the rollers, that is in the direction of movement, to the upper surface of the body of blank E. The amount of this tangential force as well as whatever rolling effect the resilient collar 36 may apply is a function of the hardness, or the compressibility, of the material used, rubber for example, and also a function of the degree of compression imposed thereon. The latter is determined by the thickness of the resilient collar 36 and also by its outer diameter as compared with the effective diameters of the swaging collars 33, 34. To secure optimum results requires a balancing of these factors, namely, the hardness of the resilient material, its thickness, and its diameter as compared with that of the swaging collars 33, 34. The type of metal of which the blank E is composed, and the thickness of the blank used are variables which influence the choice of these factors. The resilient member 36 should be of the proper thickness, diameter, and hardness to evenly counterbalance the distorting effect of the swaging of the blank edges.

The effect of using a resilient collar as 36 is to extend control over a substantial area of the blank, beyond the point of swaging or rolling, and to apply a corrective force thereto. As a specific example, in rolling standard printing plates of steel, having athickness of about .015".

and a flange thickness of about .008", rubber collars 36 of various degrees of hardness have been used. These were thick (from inner diameter to outer diameter) and were of exactly the same outer diameter as the steel rolling collars 33 and 34, the assembled roller having been ground to bring all the collars 33, 34 and 36 to the desired finished size. Rubber ranging from 35 to 98 points of hardness, as measured by the Shore Durometer, was found to cause various degrees of curvature of the plates toward the upper roller with the softer grades, and to cause curvature toward the lower roller with the harder grades. With zinc alloy plates of substantially the same dimensions, similar results were obtained, although the optimum point, where straight plates were produced, was somewhat lower than with steel plates. For zinc alloy plates of a type commonly used in printing devices adapted for use in addressing machines, and the like, a rubber collar thick having a Shore Durometer hardness of approximately '70 points of hardness and diameter exactly equal to that of collars 33, 34 was found to be satisfactory. The hardness of the metal being rolled, the thickness of the flange (or its average effective thickness in the case of a bevelled plate, Fig. 5) as compared with the full plate thickness, the thickness of the rubber collar 36 and its outside diameter which may be slightly greater than, equal to, or slightly less than that of the collars, depending upon the configuration of the rolled plate edge, are all factors of importance.

It should be emphasized that the figures given above are exemplary only and that experimentation will probably be necessary in order to select rubber of appropriate hardness for the.

collar 36, dependingupon the hardness, ductility, resilience and thickness of the material to be rolled, the extent to which portions thereof are to be reduced in thickness, and the like. It is obvious, furthermore, that although the above description applies to the rolling of printing plates, other thin plates, sheets, or continuous strips of comparable properties may be rolled by the same general method and apparatus. Obviously, when equal degrees of compression are applied to rubber collars 36 which are identical except that they are of different degrees of hardness, the collars spread out to substantially the same degree to extend control over a substan tially equal area of the plate being rolled, but the force applied to the plate is greater in the case of the harder rubber.

By the means just described I am able to roil or swage edge flanges or other portions of reduced thickness on thin metal plates or strips and to control and counteract the stresses set up in such plates by the rolling or swaging op eration so as to produce plates which are perfectly straight and show no tendency to warp or curve. Before my invention it was necessary to pass rolled plates through straightening devices such as alternating rollers and the straightenin operations were not entirely satisfactory.

As pointed out in the aforesaid Hueber et a1. application, in order to avoid the production of sharp corners on rolled plates, the corners of blanks as should be cut back slightly before rolling so as to provide smooth rounded corners when the'metal'fiows outwardly in the swaging operation. Proper design of the blank, as

formation of-sharp or ragged corners and projections which might injure operators who' later' handle the printing plates. Obviously, if desired, continuous strips of the desired width may be rolled by my method and apparatus blanks of suitable length and with corners or desired shape being .cut therefrom subsequently to the rolling-operation. Also, as suggested above, since the swaging operation causes metal in the edge portions to flow outwardly, the blank E, or the strip from which it is cut, is made slightly narrower than the final overall width desired on the plate P or :Pb. Inasmuch as the flow or metal resulting from the swaging operation is practically uniform from blank to blank (assuming there is no change in material :or thickness :of blanks as E) ultimate width of the plate will be quite accurately controlled by providing blanks E of uniform width, allowing "for expan- $1011 in the swaging process.

As noted above, and as clearly indicated in v Fig. 4, the swaging effected between the outer peripheries of rolling collars 33 and 3d and the cooperating surface of roller 25 not only causes the marginal metal to flow outwardly :but also produces some crowding of the :metal inwardly. This causes a slight head as shown at N, Fig. 4, along the upper margins of the unswaged body of the plate. The metal .is displaced upwardly rather than downwardly because the resilient collar 36 yields whereas the roller 25 has an unyielding surface. This action raises shoulders l5, l5 somewhat higher than they would have been otherwise, which stiifens the plate somewhat and is of some advantage when the plates P are mounted in a frame, :as described in the aforesaid copending application of .Hueber et ,al.

Inasmuch as millions of plate holding frames are still in use which were designed for printing plates with unswaged edges, it is desirable that one side of each plate be kept flat :and smooth so that even swaged plates may be used with the older type holding devices by placing the unswaged side uppermost, as more fully explained in the aforesaid copending application of Hueberet al. Thereioreflanges H are soformed that .one edge, the lower edge .as :seen in Fig. .4, is flush or level with the central area of the plate. This result is obtained .by the use of .a roller .25 with a hard smooth cylindrical surface as mentioned above. If a plate P, Fig. 4, :is used with the older type holding frame, type characters, and the panel areas which are raised to support them in a type embossing operation, will be formed on the lower side of the ;plate as seen in this figure, rather than in the upper side. For the newer type of holding frame, where it is desired to prevent :smudging by the plate holding tabs as aforesaid the upper side of plate P will be employed for the printing surface.

It should be noted that the swaged flanges 12, Fig. 4, are not necessarily continuous throughout the length o-fa plate .P. If the plate is of plain rectangular form, ordinarily the swaged flanges l2 would run continuously along the two longer edges thereof. .If the longer edges are serpentine, as in Gollwitzer Patent No. 1,955,803, the flanges would be discontinuous. of flange obviously could beformed by :my method and in my apparatus. Obviously, also, flanges of either type could be formed on only one edge of a plate, if desired.

Most of the foregoing discussion :applies to the formation of iflanges or swaged portions of substantially uniform thickness on the edges of printing plate blanks as shown :iniig. '4. How- 8. ever, it may be advantageous in some cases to form swaged portions of other configurations for cooperation with plate holding means on print ing device frames or -'carriers. Therefore, another form of plate, with beveled edge portions adapted for cooperation with retaining :means that are not of uniform thickness, is shown in Fig. 5. The plate Pb is used in the same general type of frame or carrier as the plate I, Fig. 4,

with appropriate modifications in the plate hold ing means not necessary to describe or illustrate here. The longer marginal edges of plate Pb are swaged by a rolling, coining, extruding or like forming operation, the forming means, such as rolling collars 3'3, 34, being shaped on their outer peripheral surfaces so as to produce. the type of edge portion illustrated in Fig. 5 rather than that in Fig. 4. The corners 11b where "the beveled edge portions meet the upper surface of plate Pb are preferably roundedslightlytoeliminate any'slight ridge and to prevent formation of a sharp cutting edge. This rounded edge is obtained by properly shaping the rolling collars .33, 34.

.As in the case of plate P with flanges I2. one face, (the lower as shown in Fig. .5) of each of the flange portions I2b lies flush with one face of the plate Pb, while the other face ,of the flange portions will be out of alignment with and generally below the other surface of the plate.

As suggested above flanges as 12, 4, .of as 52b, Fig. 5,, may .be formed either on indiyidual blanks E, or on strip material which is later cut into plate blanks. In the latter case, and as more fully described in the aforesaid co pending application of Hueber et al., the strip is preferably notched appropriately on .both edges opposite the point where blanks are to be cut so that the rolling or 'swaging operation will provide rounded corners and minimize the probability of injury to persons subsequently called upon to handle the plates, as mentioned certain portions are swaged as described above,

Either type is applicable not only to individual blanks and strips of. a width corresponding to the width of .a. single blank (with allowance for the minor changes in width due to .swaging, extruding and the like as pointed out above}, but also to blanks and strips of widths corresponding to multiples of the desiredflnished width. Broadlymymethod involves the close control, by carefully selected means, of the stresses imparted to a. blank and the flow of metal which occurs therein during swaging or rolling operations on selected portions of the blank. The application of .-resilient pressure and the retention .ofcontrol .over the blank beyond the precise point of swaging, because of the elongation and flow of the resilient means employed in my method. and ap paratus, make it possible :to produce smooth 7 By. proper shaping of the corners, of the points straight plates of uniform dimensions.

where corners are ultimately to be located,- blanks are produced which are free from ra ed or unduly sharp edges, corners, or projections of any sort.

It will be understood that flanges as 4-21) may, be either continuous-or discontinuous, .as is also the case with flanges [2.- Other modifications in the cross-sectionalshapeof flanged portions I 2 or 12b, may be made, the particular formations shown being merely the shapes deemed preferable at this time. It is desirable, as suggested above, that the predetermined configuration which is imparted to the marginal edge of a printing plate be of such nature that the plate retaining means on older type plate frames or carriers may be used with swaged plates. This requires that at least a portion of the margin be substantially flush with one face of the plate.

It will be appreciated that the formation of swaged margins, as on thin metal plates of the type described above, is a precision operation where tolerances are very close. The method and apparatus described above have been found to be entirely satisfactory for the production of printing plates to rigid specifications. It will be appreciated that changes may be made in both the method and the apparatus without departing from the spirit of my invention and that either or both may be applied to the formation of portions of reduced thickness other than marginal portions on various types of plates for various purposes. It will also be understood that while I have illustrated and described selected embodiments of my invention such embodiments are capable of wide and varied modification. I therefore do not wish to be limited to the precise details set forth but I desire and intend to avail myself of any and all such changes and alterations as fall within the purview of the following claim.

I claim:

In an apparatus for rolling to produce marginal portions of reduced thickness on metal printing plates, cooperating swaging means comprising a hard backing roller, a swaging roller cooperating therewith, said swaging roller comprising opposed swaging collar members adapted to apply swaging pressure to said marginal portions to create said reduced thickness, and a resilient control member intermediate said collars, means for accurately adjusting said swaging roller to position the swaging collars thereon in proper swaging position and in opposed overlapping relation to said backing r011, said resilient member having a selected degree of hardness such that its compression against intermediate areas of a printing plate in the course of a swaging operation, spreads the contact of its surface so as to apply a straightening force to said plate and to allow the flow of metal inwardly of said rollers to extrude from the surface of the plate to avoid bending strain on the central portion of the plate and thereby prevent any tendency of said plate to curve by reason of strains set up by said cooperating swaging means.

GASPAR P. BEN'ES.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

